Dioptrical Paradox

This boxed set of six double-sided views and viewer are from the scientific instrument makers and dealers W & S Jones, 30 Holborn.

This extraordinary optical amusement is a form of an anamorphic view. There is an image in the center of the plate. When looking through the eye piece other parts of the image on the periphery of the plate are gathered by the prism to produce a new image.